Multilaboratory Comparison of Omadacycline MIC Test Strip to Broth Microdilution MIC against Gram-Negative, Gram-Positive, and Fastidious Bacteria.

The performance of the Liofilchem omadacycline MIC Test Strip (MTS) was evaluated in a multisite study. Three testing sites collected/tested clinical isolates and one site tested challenge isolates that totaled 175 S. aureus, 70 S. lugdunensis, 121 E. faecalis, 100 E. faecium, 578 Enterobacterales, 142 Haemophilus spp., 181 S. pneumoniae, 45 S. anginosus group, 35 S. pyogenes,and 20 S. agalactiae. MIC testing was performed by CLSI broth microdilution (BMD) and MTS. Fastidious isolates testing included BMD and MTS testing with both CLSI and EUCAST Mueller-Hinton Fastidious (MH-F). In addition, each site performed reproducibility for nonfastidious and fastidious isolates and QC by MTS and BMD. All BMD and MTS results for the QC strains were within expected ranges, with exception of one MTS HTM result for H. influenzae ATCC 49247. Among reproducibility isolates, omadacycline MTS results were within one dilution of the modal MIC for 95.2% of nonfastidious Gram-positive, 100% of Gram-negative, 99.3% and 98.5% of fastidious isolates tested on CLSI and EUCAST media, respectively. MTS results for all study isolates were within one doubling dilution of the CLSI BMD MIC for 98.9% of S. aureus, 100% of S. lugdunensis, 98.3% of E. faecalis, 100% of E. faecium, and 99.6% of Enterobacterales. Essential agreement rates for CLSI and EUCAST MH-F agar compared to CLSI BMD were 98.2% and 98.2%, for H. influenzae, 91.1% and 73.6%, for S. pneumoniae and 100% and 85-91.7% for other streptococcus species, respectively. Based on CLSI media, all categorical errors were minor errors and categorical agreement rates were >90% with exception of C. freundii, S. lugdunensis, E. faecalis, S. anginosus and S. constellatus.

Multilab evaluation of delafloxacin MIC Test Strip against Gram-negative and Gram-positive organisms.

The performance of the delafloxacin MIC Test Strip (MTS) was evaluated. Three testing sites collected/tested clinical isolates, and 1 site tested challenge isolates that together total 224 S. aureus, 36 S. haemolyticus, 23 S. lugdunensis, 105 E. faecalis, 308 Enterobacteriales, and 140 P. aeruginosa. MIC testing was performed by broth microdilution (BMD) and MTS. Each site also tested 20 common isolates in triplicate on 3 days by MTS and 20 replicates of 4 QC strains by MTS and BMD. MTS results for consolidated clinical/challenge isolates were within 1 doubling dilution of the BMD MIC for 96.9% of S. aureus; 100% of S. haemolyticus, S. lugdunensis, and E. faecalis; 98.4% of Enterobacteriales; and 97.9% of P. aeruginosa. All reproducibility results were within 1 dilution of the modal MIC. All BMD and MTS results for the QC strains were within expected ranges. Overall, the delafloxacin MTS performed similar to BMD.

Clinical features and outcomes of spitzoid proliferations in children and adolescents.

BACKGROUND: Spitzoid proliferations range from Spitz naevi to melanomas. There are few studies describing clinical features and outcomes in the paediatric population. OBJECTIVES: To determine the clinical features and outcomes of a large paediatric cohort with histopathologically confirmed Spitz tumours. METHODS: This was a retrospective cohort study of patients seen at Boston Children's Hospital who were aged < 20 years and had a histopathological diagnosis of spitzoid proliferation from 1 January 1994 to 23 October 2012. RESULTS: In total 595 patients with 622 spitzoid proliferations were identified (median age 7·4 years, interquartile range 4·6-11·7). Overall 512 proliferations (82·3%) were typical, 107 (17·2.%) were atypical and three (0·5%) were melanomas. The median ages at biopsy were 7·4, 7·2 and 17·2 years, respectively, and there was a significant difference in age at biopsy for patients with typical or atypical proliferations vs. melanoma (P < 0·01). Among samples with positive margins (n = 153), 55% (54 of 98) of typical proliferations, 77% (41 of 53) of atypical proliferations and 100% (two of two) of melanomas were re-excised. Six patients had sentinel lymph node biopsy performed, with three patients demonstrating nodes positive for melanocytic cells. Within a median follow-up of 4·1 years for the full cohort there were no related deaths. CONCLUSIONS: Spitz tumours have strikingly benign outcomes in the paediatric population, although this study is limited by the low number of melanomas and restriction to a single paediatric institution. Aggressive management recommendations should be reconsidered for children and adolescents with banal-appearing Spitz naevi, based on the clinically indolent behaviour in this cohort.

Analysis of MIC and Disk Diffusion Testing Variables for Gepotidacin and Comparator Agents against Select Bacterial Pathogens.

This study was conducted to determine the effect of testing parameters on the in vitro activity of gepotidacin, a new triazaacenaphthylene antibacterial agent for the treatment of conventional and biothreat pathogens. CLSI methods, and variations of those methods, were used to test 10 Staphylococcus aureus, 10 Streptococcus pneumoniae, 10 Haemophilus influenzae, and 5 Escherichia coli isolates by MIC and 30 S. aureus, 15 S. pneumoniae, and 15 S. pyogenes isolates by disk diffusion (DD) methods. Levofloxacin and linezolid were tested as comparator agents for MIC and DD methods, respectively. Broth microdilution (BMD), macrodilution (MD), and agar dilution (AD) methods were compared. Variations in media, temperature, incubation time, CO2 level, and inoculum concentration were tested by all methods, and variations in pH, calcium, magnesium, zinc, potassium, thymidine, and polysorbate 80 levels were tested by BMD and DD. The addition of albumin, serum, and lung surfactant was studied by BMD. The variables that impacted the results the most were high inoculum and pH 5.5 (no growth of H. influenzae and S. pneumoniae by BMD). Gepotidacin AD MIC levels were increased and disk zone diameters were decreased for all species in 10% CO2 incubation. The following variables had a minimal effect on gepotidacin results: pH, agar method, atmospheric condition, temperature, and addition of serum and albumin for broth methods. There were also some slight differences in gepotidacin disk results between disk manufacturers and some agar types and also with potassium and thymidine for S. pneumoniae For all other variations, gepotidacin MIC and disk results were considered comparable to reference results.

Geriatrics for juniors: tomorrow's geriatricians or another lost tribe?

BACKGROUND: To meet the needs of the ageing population, more geriatric medicine doctors are required. We aimed to determine: (i) career preferences of junior doctors with an interest in geriatric medicine, (ii) factors influencing the likelihood of junior doctors undertaking a career in geriatric medicine and (iii) whether a geriatric medicine conference for junior doctors influenced their views on the specialty and their likelihood of choosing it as a career option. METHODS: All delegates who registered to attend the 'Geriatrics for Juniors' conference (G4J) were invited to complete both a pre- and post-conference survey online. Delegates' free-text responses were subjected to thematic analysis. Differences between paired ordinal data from pre- and post-conference surveys were determined using the Wilcoxon signed rank test. RESULTS: A total of 108 delegates attended G4J. Pre- and post-conference survey response rates were 67% and 51% respectively. Commonly reported deterrents to a career in geriatric medicine included 'being the medical registrar' (27.1% of respondents) and 'second-class specialty' (20.6%). There was a statistically significant difference between pre- and post-conference responses, with a tendency towards less agreement with the statement 'the prospect of being the medical registrar puts me off applying for higher specialty training in geriatric medicine' (Z=-2.512; p=0.012). CONCLUSIONS: The perceived unattractive nature of the medical registrar role may deter some junior doctors from a career in geriatric medicine. A lack of clarity regarding the nature of the specialty still exists. Targeted educational interventions, such as G4J, may positively influence junior doctors' perceptions of the specialty and the role of the medical registrar.

Diagnosis and management of acute kidney injury: deficiencies in the knowledge base of non-specialist, trainee medical staff.

Enhanced education has been recommended to improve non-specialist management of acute kidney injury (AKI). However, the extent of any gaps in knowledge has yet to be defined fully. The aim of this study was to assess understanding of trainee doctors in the prevention, diagnosis and initial management of AKI. An anonymised questionnaire was completed by hospital-based trainees across Newcastle Renal Unit's catchment area. Responses were evaluated against a panel of pre-defined ideal answers. The median score was 9.5 out of 20 (n = 146; range 0-17) and was lower in more junior trainees. Fifty percent of trainees could not define AKI, 30% could not name more than two risk factors for AKI and 37% could not name even one indication for renal referral. These serious gaps in knowledge highlight the need for enhanced education aimed at all training grades. Organisational changes may also be required to optimise patient safety.

Interactive effects of nitrogen deposition and fire on plant and soil chemistry in an alpine heathland.

The response of alpine heathland vegetation and soil chemistry to N additions of 0, 10, 20 and 50 kg N ha(-1) year(-1) in combination with simulated accidental fire (+/-) was monitored over a 5-year period. N addition caused rapid and significant increases in plant tissue N content and N:P and N:K of Calluna vulgaris, suggesting increasing phosphorus and potassium limitation of growth. Soil C:N declined significantly with N addition, indicating N saturation and increasing likelihood of N leakage. Fire further decreased soil C:N and reduced potential for sequestration of additional N. This study shows that alpine heathlands, which occupy the headwaters of many rivers, have limited potential to retain deposited N and may rapidly become N saturated, leaking N into downstream communities and surface waters.

Attributable risk of alcohol and other drugs for crashes in the transit industry.

OBJECTIVE: To estimate the impact of employee alcohol and drug use on crashes in the transit industry from 1995-2000. DESIGN: Secondary analysis of federally mandated post crash and random alcohol and drug testing results. SETTING: The US transit industry. SUBJECTS: Transit industry employees. MAIN OUTCOME MEASURES: Relative risk (RR), population attributable risk (PAR), and population attributable risk percentage (PAR%). RESULTS: For alcohol testing, the estimated PAR% ranged from 0.02% (1999) to 0.03% (1995). For drug testing, the estimated PAR% ranged from 0.38% (1998) to 0.67% (1997). Based on these calculations, the estimated number of crashes per 1000 crashes attributable to alcohol was less than one during 1995-2000, and the number attributable to drugs ranged from about four to about six. The number of crashes attributable to either alcohol or drugs did not vary greatly from 1995-2000. Estimated rates of crashes attributable to alcohol or drugs were substantially lower in 1995, the first year of testing, than had been projected based on previous estimates, and did not show substantial change from 1995-2000. CONCLUSIONS: Approaches to transit safety based on reducing employee use of alcohol and other drugs have modest potential for reducing number of fatalities, injuries, and crashes.

DFT and in situ EXAFS investigation of gold/ceria-zirconia low-temperature water gas shift catalysts: identification of the nature of the active form of gold.

A combined experimental and theoretical investigation of the nature of the active form of gold in oxide-supported gold catalysts for the water gas shift reaction has been performed. In situ extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) experiments have shown that in the fresh catalysts the gold is in the form of highly dispersed gold ions. However, under water gas shift reaction conditions, even at temperatures as low as 100 degrees C, the evidence from EXAFS and XANES is only consistent with rapid, and essentially complete, reduction of the gold to form metallic clusters containing about 50 atoms. The presence of Au-Ce distances in the EXAFS spectra, and the fact that about 15% of the gold atoms can be reoxidized after exposure to air at 150 degrees C, is indicative of a close interaction between a fraction (ca. 15%) of the gold atoms and the oxide support. Density functional theory (DFT) calculations are entirely consistent with this model and suggest that an important aspect of the active and stable form of gold under water gas shift reaction conditions is the location of a partially oxidized gold (Audelta+) species at a cerium cation vacancy in the surface of the oxide support. It is found that even with a low loading gold catalysts (0.2%) the fraction of ionic gold under water gas shift conditions is below the limit of detection by XANES (<5%). It is concluded that under water gas shift reaction conditions the active form of gold comprises small metallic gold clusters in intimate contact with the oxide support.

Induction of CYP3A4 by 1 alpha,25-dihydroxyvitamin D3 is human cell line-specific and is unlikely to involve pregnane X receptor.

Under certain culture conditions, exposure of the human colon adenocarcinoma cell line Caco-2 to 1,25-(OH)(2)-D(3) induces expression of CYP3A4 to levels comparable to that in human small intestinal epithelium. To determine whether 1,25-(OH)(2)-D(3) could be used to restore CYP3A expression in other culture models, we examined several cell lines derived from malignancies of human tissues known to express CYP3A enzymes: Hep G2 (liver), LS180 (colon), HPAC (pancreas), Hs746T (stomach). Primary cultures of human hepatocytes from two donors were also examined. 1,25-(OH)(2)-D(3) increased CYP3A catalytic activity in LS180 (15-fold), HPAC (6-fold), and hepatocytes (2- to 3-fold); this was accompanied by induction of CYP3A4 mRNA and CYP3A immunoreactive protein. However, 1,25-(OH)(2)-D(3) had no effect on CYP3A expression in Hs746T or Hep G2. Known ligands for pregnane X receptor (PXR) (rifampin, dexamethasone, and dexamethasone t-butyl acetate) markedly induced CYP3A4 expression in human hepatocytes. In contrast, these ligands had little or no effect on CYP3A4 expression in Caco-2 cells, even at concentrations 1 to 2 orders of magnitude greater than effective concentrations of 1,25-(OH)(2)-D(3) or two other vitamin D receptor (VDR) ligands (25-OH-D(3) and 1-OH-D(3)). The retinoic acid receptor ligand all-trans-retinoic acid augmented the 1,25-(OH)(2)-D(3)-mediated induction of CYP3A4 catalytic activity up to 2-fold in Caco-2 cells, while having no demonstrable effect on levels of CYP3A4 mRNA or protein. The retinoid X receptor ligand 9-cis-retinoic acid appeared to slightly reduce CYP3A4 catalytic activity. We conclude that 1,25-(OH)(2)-D(3) can be used to increase CYP3A4 expression in some, but not all, human cell lines derived from tissues known to express CYP3A enzymes. The mechanisms involved in this induction are unlikely to involve PXR and may involve VDR.

Disaster coordination and management: summary and action plans.

INTRODUCTION: Disaster is a collective responsibility requiring coordinated response from all parts of society. This theme focused on coordination and management issues in a diverse range of scenarios. METHODS: Details of the methods used are provided in the preceding paper. The chairs moderated all presentations and produced a summary that was presented to an assembly of all of the delegates. Although the main points developed in Themes 1 and 4 were different from each other (as reported in the Results section), their implementation was similar. Therefore, the chairs of both groups presided over one workshop that resulted in the generation of a set of Action Plans that then were reported to the collective group of all delegates. RESULTS: The main points developed during the presentations and discussions included: (1) the need for evidence-based assessments and planning, (2) the need for a shift in focus to health-sector readiness, (3) empowerment of survivors, (4) provision of relief for the caregivers, (5) address the incentives and disincentives to attain readiness, (6) engage in joint preparation, response, and training, (7) focus on prevention and mitigation of the damage from events, and (8) improve media relations. There exists a need for institutionalization of processes for learning from experiences obtained from disasters. DISCUSSION: Action plans presented include: (1) creation of an Information and Data Clearinghouse on Disaster Management, (2) identification of incentives and disincentives for readiness and develop strategies and interventions, and (3) act on lessons learned from evidence-based research and practical experience. CONCLUSIONS: There is an urgent need to proactively establish coordination and management procedures in advance of any crisis. A number of important insights for improvement in coordination and management during disasters emerged.

Identification of Candida dubliniensis in a HIV-positive South African population.

Candida dubliniensis was identified as a distinctly separate species of the genus Candida in 1995. Since then the yeast has attracted considerable interest due to its prevalence in HIV/AIDS patients and its ability to develop fluconazole resistance in HIV-seropositive individuals. Although C. dubliniensis has been identified in many centres around the world it has not yet been isolated in Africa. The purpose of this study was to identify C. dubliniensis in an HIV-positive population in the Western Cape, South Africa. A cohort of 50 tuberculosis patients co-infected with HIV was selected on admission to the Brooklyn Chest Hospital, Western Cape. The inclusion criteria for patients accepted for the study were: confirmed HIV seroconversion with a diagnosis of tuberculosis obtained from chest X-rays and sputum microscopy. C. dubliniensis was identified in 6 of the 50 patients accepted onto the study. The prevalence of C. dubliniensis in our study population was lower than that reported in similar North American and European studies. These results confirm the presence of C. dubliniensis in the South African HIV/AIDS population and indicate the urgent need for further investigations into the prevalence and pathogenesis of this clinically important species in both adult and paediatric HIV-positive patients.

Occupational stress factors and alcohol-related behavior in urban transit operators.

BACKGROUND: If alcohol consumption mitigates psychological and physiological aspects of the response to stressors, then alcohol consumption might be elevated for individuals exposed to high occupational stressors. Frequency of work stressors and reaction to those stressors were studied in relation to several alcohol-related outcomes. METHODS: During the period 1993-1995, 1979 transit operators underwent medical examinations for commercial driver's license renewal. Questionnaire and interview data concerning occupational stress factors and alcohol-related outcomes were available for 1386 (70.2%) of the operators. RESULTS: A positive association was found between the two job stressor-related measures and each of six alcohol-related outcomes. Of these 12 associations, ten were statistically significant. Individuals experiencing high self-reported frequency of job stressors and a higher perceived severity of those job stressors were more likely to drink and more likely to be heavy drinkers. They reported more consequences of alcohol consumption, reported increased consumption since beginning work as transit drivers, and were more likely to report drinking to deal with work stress. They also drank more, but this effect was not significant for either job stress measure. There was virtually no association between either stressor-related measure and alcohol dependency (CAGE). CONCLUSIONS: Together with other published findings, these results suggest increased alcohol-related outcomes in the presence of work stressors. This conclusion has potential implications for worksite health promotion and job design. Because our findings are cross-sectional, further research is needed to clarify the causal nature of the work stressor-alcohol association. Further research also is needed to clarify the role of individual differences and context.

Racial discrimination and alcohol-related behavior in urban transit operators: findings from the San Francisco Muni Health and Safety Study.

OBJECTIVE: A growing body of literature is documenting the health effects of racial discrimination. The authors investigated the association between racial discrimination and alcohol-related behavior in a sample of urban transit operators. METHODS: Using data from a 1993-1995 cross-sectional study of transit operators in San Francisco, California, the authors analyzed responses to two sets of questions about racial discrimination; the first set focused on reaction to unfair treatment and the second on arenas, or domains, of discrimination. Alcohol-related variables were: number of drinks per month, heavy drinking, alcohol dependence, and negative consequences of alcohol consumption. RESULTS: Operators who reported five or more domains of discrimination drank an average of 13.4 more drinks per month than those who reported no domains of discrimination (P = 0.01). Similarly, they were more likely to be heavy drinkers (adjusted odds ratio [OR] = 2.16; 95% confidence interval [CI] 1.14, 4.09) and dependent on alcohol (adjusted OR = 2.02; 95% CI 1.08, 3.79) than operators who reported no domains of discrimination. The number of domains in which operators reported having experienced discrimination was not related to sex, age, household income, job seniority, or marital status, but varied significantly by educational level and race/ethnicity. CONCLUSIONS: Data from a sample of urban transit operators showed an association between the number of domains of discrimination and some alcohol-related outcomes, but not others.

Quantitative measurement of mast cell degranulation using a novel flow cytometric annexin-V binding assay.

BACKGROUND: Mast cells are primary mediators of allergic inflammation. Antigen-mediated crosslinking of their cell surface immunoglobulin E (IgE) receptors results in degranulation and the release of proinflammatory mediators including histamine, tumor necrosis factor-alpha, and leukotrienes. METHODS: Mast cells were stimulated to degranulate by using either IgE crosslinking or ionophore treatment. Exogenously added annexin-V was used to stain exocytosing granules, and the extent of binding was measured flow cytometrically. Release of the enzyme beta-hexosaminidase was used for population-based measurements of degranulation. Two known inhibitors of degranulation, the phosphatidylinositol 3 kinase inhibitor wortmannin and overexpression of a mutant rab3d protein, were used as controls to validate the annexin-V binding assay. RESULTS: Annexin-V specifically bound to mast cell granules exposed after stimulation in proportion to the extent of degranulation. Annexin-V binding was calcium dependent and was blocked by phosphatidylserine containing liposomes, consistent with specific binding to this membrane lipid. Visualization of annexin-V staining showed granular cell surface patches that colocalized with the exocytic granule marker VAMP-green fluorescent protein (GFP). Wortmannin inhibited both annexin-V binding and beta-hexosaminidase release in RBL-2H3 cells, as did the expression of a dominant negative rab3d mutant protein. CONCLUSIONS: The annexin-V binding assay represents a powerful new flow cytometric method to monitor mast cell degranulation for functional analysis.

Workplace discrimination and alcohol consumption: findings from the San Francisco Muni Health and Safety Study.

OBJECTIVE: There is evidence of an association between occupational stress and alcohol consumption. This study investigates the association between workplace racial discrimination and alcohol consumption in a sample of urban transit operators. METHODS: During 1993-1995, after undergoing a medical exam, 1,542 transit operators completed an interview. Depending on the outcome, we used logistic or linear regression models to examine the cross-sectional relationship between discrimination experience and alcohol consumption. RESULTS: Operators who reported discrimination in at least one situation, out of a possible four, were more likely to have had negative life consequences as a result of drinking (adjusted OR = 1.97; 95% CI, 1.20-3.83) and were more likely to be classified as having an alcohol disorder (OR = 1.56 [0.96-2.54]), compared to those who reported no instances of workplace discrimination. Results adjusted simultaneously for age, sex, race/ethnicity, education, income, marital status, and seniority. There was no association between workplace discrimination and heavy drinking or drinks per month. CONCLUSIONS: Cross-sectional data from a sample of urban transit operators indicates an association between workplace racial discrimination and some measures of alcohol consumption.

First-pass midazolam metabolism catalyzed by 1alpha,25-dihydroxy vitamin D3-modified Caco-2 cell monolayers.

Cytochrome P-450 (CYP) 3A4 accounts for approximately 50% of all P-450s found in the small intestine (Paine et al., 1997) and contributes to the extensive and variable first-pass extraction of drugs such as cyclosporine and saquinavir. We recently demonstrated that CYP3A4 expression in a differentiated Caco-2 subclone is increased when cell monolayers are treated with 1alpha,25-dihydroxy-vitamin-D3 (Schmiedlin-Ren et al., 1997). This improved metabolic capacity permits the in vitro modeling of first-pass intestinal metabolic kinetics. Midazolam (MDZ) 1'-hydroxylation was used as a specific probe for CYP3A-mediated metabolism in modified Caco-2 monolayers. Caco-2 cells were grown to confluence on laminin-coated culture inserts, and then for two additional weeks in the presence of 1alpha,25-dihydroxy vitamin-D3. Cell monolayers were subsequently exposed to MDZ for varying lengths of time and concentrations. The amount of MDZ in the monolayer increased rapidly after apical drug administration, reaching a pseudo steady state within 6 min. The cellular uptake rate was considerably slower after a basolateral dose. By either route of administration, the rate of 1'-hydroxymidazolam formation was stable and linear for 2 h. Under basolateral sink conditions and low apical MDZ dosing concentration (1-8 microM), the first-pass extraction ratio was found to be approximately 15%. Higher dosing concentrations led to saturation of the hydroxylation reaction and reduction in the extraction ratio. The modified Caco-2 cell monolayer is an excellent model for studying drug absorption and first-pass intestinal metabolic kinetic processes. In this system, the selective CYP3A probe MDZ was rapidly absorbed, yet extensively metabolized, as is observed in vivo.

Midazolam metabolism by modified Caco-2 monolayers: effects of extracellular protein binding.

It has been suggested that the binding of a drug to plasma proteins will influence the intestinal extraction efficiency when drug is delivered to the mucosal epithelium via either the gut lumen or vasculature. We evaluated this hypothesis using cytochrome P-450 (CYP)3A4-expressing Caco-2 monolayers as a model for the intestinal epithelial barrier and midazolam as a CYP3A-specific enzyme probe. The rate of 1'-hydroxylation was measured following apical or basolateral midazolam administration to monolayers incubated in the presence or absence of 4 g/dl of human serum albumin (HSA) in the basolateral compartment medium. The midazolam-free fraction in culture medium containing HSA was 3.3%. Inclusion of HSA in the basolateral medium decreased peak intracellular midazolam accumulation after an apical midazolam dose (3 microM) by 35% and reduced the 1'-hydroxymidazolam formation rate by approximately 20%. Because of the accelerated diffusion of midazolam through the cell monolayer and into the basolateral compartment, there was a 61% reduction in the first-pass metabolic extraction ratio: 13.3 +/- 0. 12% for control versus 5.2 +/- 1% with HSA. Compared with control, addition of HSA resulted in a 91% decrease in the peak intracellular midazolam level and a 86% decrease in the rate of 1'-hydroxylation after the administration of midazolam into basolateral medium. These findings suggest that, in vivo, binding of a drug to plasma proteins will impact both first-pass and systemic intestinal midazolam extraction efficiency. Furthermore, the effect will be more pronounced for a drug that is delivered to mucosal enterocytes by way of arterial blood, compared with oral drug delivery.